Stuart McLachlan
stuart at lexacorp.com.pg
Fri Sep 25 16:16:21 CDT 2009
VirtualBox , VirtualPC etc are Type 2 Hypervisors
If you want a Type 1, it is going to cost you.
Straight steal from Wikipedia:
Hypervisors are classified in two types:[1]
* Type 1 (or native, bare-metal) hypervisors are software systems that run directly on the
host's hardware as a hardware control and guest operating system monitor. A guest
operating system thus runs on another level above the hypervisor.
This is the classic implementation of virtual machine architectures; the original hypervisor
was CP/CMS, developed at IBM in the 1960s, ancestor of IBM's current z/VM.
More recent examples are VMware ESX Server, LynxSecure from LynuxWorks, L4
microkernels including OKL4 from Open Kernel Labs, Real-Time Systems RTS-Hypervisor,
VirtualLogix VLX, TRANGO (now VMware MVP), IBM POWER Hypervisor (PowerVM), IBM
System z Hypervisor (PR/SM), Microsoft Hyper-V (released in June 2008), Xen, Citrix
XenServer, Oracle VM Server, Parallels Server (released in 2008), ScaleMP vSMP
Foundation (released in 2005) , Sun's Logical Domains Hypervisor (released in 2005), Wind
River's hypervisor and VxWorks MILS Platform, XtratuM.
...
* Type 2 (or hosted) hypervisors are software applications running within a conventional
operating system environment. Considering the hypervisor layer being a distinct software
layer, guest operating systems thus run at the third level above the hardware.
Examples include VMware Server (formerly known as GSX), VMware Workstation,
VMware Fusion, the open source QEMU, Microsoft Virtual PC and Microsoft Virtual Server
products, Sun's (formerly InnoTek) VirtualBox, KUKA's [RTOSWin] [1] product family as
well as Parallels Workstation and Parallels Desktop and TenAsys' eVM.
--
Stuart
On 25 Sep 2009 at 11:37, Arthur Fuller wrote:
> Although I have made everything work satisfactorily, I still am mystified
> and concerned that things are inverted. It seems that I must run a basic OS,
> whether Ubuntu or XP or Windows Server, and then run VirtualBox inside this
> OS. This seems to be fundamentally backwards: the first thing that boots
> ought to be a minimal OS + VirtualBox or any similar VM manager: the lowest
> level ought to be just that -- no applications at all, save the VM manager,
> thus preserving the max RAM for the VMs. Given such a layout, I could then
> create a dozen VMs and stuff only the apps of interest into each of them,
> e.g. Vista in one, XP in another, Ubuntu in another, etc.
> This is pretty much what I do anyway, despite the overhead of the first OS,
> but I currently live with it (and also with my impecuniousness -- would love
> to cram 8GB in this sucker!). Ah well, another day....
>